Cities

Decisions made to improve performance:

• Use Array and indexes so it doesn't duplicate objects
• Create a nameLowerCase field on the model to avoid using String.toLowerCase() all the time
• Create a hashmap that holds all indexes for the first two characters, so the search on the beginning (when the list is bigger) is O(1)

To-Do:

• Improve UI all around
• Refactor the CityDetailFragment to use MVP and be testable
• Improve test coverage on the search
• Decouple more the DataSource and the Presenter on the list
  • (it's kinda fuzzy that the presenter knows how the DataSource stores the indexes)